1. Field of the Invention
The present invention relates to an endoscope which applies a propulsion force in a direction of insertion axis of an insertion portion thereof corresponding to rotation of the insertion portion based on a driving force of a driving member, an endoscope system, and a method of manufacturing the endoscope.
2. Description of Related Art
Conventionally, an endoscope for medical use has been widely used. The endoscope, for example, can provide observation of an affected part and the like within a body cavity by inserting an elongated insertion portion into the body cavity and various treatments using a treatment instrument inserted into a forceps channel as needed. The endoscope includes on a distal end side of the insertion portion thereof a freely bendable bending portion. In the endoscope, the bending portion is bent and operated in up/down and left/right directions by operation of a bending operation knob.
When the endoscope device is inserted into a convoluted intracavital canal, for example, a lumen forming a loop of 360 degrees such as the large intestine, the bending portion is bent and operated by the operation of the bending operation knob, while the insertion portion is operated and twisted to be inserted toward an observation target position.
However, such an operation of the endoscope requires mastery to be able to insert the insertion portion smoothly in a short period of time into a deep part in the convoluted large intestine. Therefore, it is concerned that an inexperienced operator, in inserting the insertion portion into the deep part in the large intestine, loses the insertion direction and has trouble in the insertion, and greatly changes the way the intestine runs.
Therefore, various proposals have conventionally been made for improving the insertability of the insertion portion. For example, Japanese unexamined patent publication No. 10-113396 discloses a propulsion device for medical apparatus capable of easily and low-invasively guiding a medical apparatus into a deep part of an intracavital canal.
The propulsion device has a rotation member provided in the axial direction thereof with a diagonal rib serving as a propulsion force generating portion. Accordingly, in the propulsion device described in the above-described publication, with rotational motion of the rotation member, rotational force of the rotation member is converted into a propulsion force by the rib, and the medical apparatus linked to the propulsion device is moved toward the direction of the deep part of the intracavital canal by the propulsion force. According to this, the propulsion device described in Japanese unexamined patent publication No. 10-113396 is capable of inserting the medical apparatus into a body cavity without putting a physical burden on a patient.